If you want it to generate on the client and also have muliple clients use the program the only thing you can do is have a tble that holds the current record counter. Then have your client read this value from the SQL table (make sure you deal with locking!) and increment it by one. It can then use this new value as the new record primary key.

Note: This is not a good way to do it as a table that holds a single field defies normalization.